Animal Migrations

Wolves and bears migrate through a forest, one group per migration. The type of each migration depends only on the type of the previous one:

• If the current migration is by wolves, the next is by wolves with probability 90% and by bears with probability 10%.
• If the current migration is by bears, the next is by bears with probability 60% and by wolves with probability 40%.

The current migration is by wolves. What is the expected number of migrations, counting the next wolf migration itself, until the next wolf migration occurs? Give the answer as a decimal number.